The very worst of the cyclone missed the small central Queensland coastal town but it still brought destructive winds of up to 141km/h.

Former Rockhampton resident Carmel Barnfield on the Gold Coast said her Yeppoon sister Anne Maree's family was huddled together inside their bathroom at Yeppoon worried about losing the roof on their home.

"They think they are losing their roof and they are not moving," Carmel said on Friday.

"She is in Yeppoon, about 10 kilometres west of the main part of town, in Barmaryee."

"It's a big home, it's a farm.

"There has been roof damage already and they have lost everything, all their sheds; their boat shed, their granny flat."

At 2pm, the cyclone's most destructive core was about five kilometres south-southwest of Rockhampton, surging south at about 20km/h an hour.

Marcia was downgraded to category three at 1pm but was still producing wind gusts of up to 205km/h.

Residents along the Capricornia Coast in central Queensland have been warned to remain inside, particularly those in Yeppoon and Rockhampton.

Queensland Premier Annastacia Palaszczuk urged people to stay alert.

"My message to all the people in Yeppoon and those coastal areas is please still stay indoors," she said shortly after noon.

"Still stay indoors, do not leave your home, do not go outside, please stay where you are.

"We have heard of some reports of flooding, starting to occur now in Rockhampton.

"So my message to all of Rockhampton residents is please stay indoors.

"The eye of this storm is headed directly towards you."

A cyclone warning is current for Shoalwater Bay to Double Island Point, extending inland to Moura, Biloela, Monto, and Mundubbera.

Shayne Harris and her two children were hunkered down in Yeppoon's St Brendan's College chapel as the cyclone passed.

They left their home in Byfield, close to where Tropical Cyclone Marcia made landfall, on Thursday because they were worried about danger from trees nearby.

She is hoping for the best when she returns but is worried there will be nothing left.

"From a neighbour there they said there's no leaves on the trees and trees are falling over," she said.

"We're just hoping that things aren't too bad.

"The problem is that even when this is all over we won't be able to get home until all the creeks go down because it floods out there."

Airlines have cancelled a string of flights to affected areas, including those to Bundaberg, Gladstone, Hervey Bay and Rockhampton.

Brisbane was bearing up "reasonably well" with the rain it has received to date, Lord Mayor Graham Quirk told reporters on Friday morning.

The Bureau of Meteorology warned rain falling throughout Friday in south-east Queensland was from a separate trough and was likely to intensify as the cyclone tracked further south.

Dozens of roads on the Sunshine Coast, Brisbane and the Gold Coast have been flooded.

A severe weather warning is current for damaging winds, heavy rainfall, abnormally high tides, dangerous surf in areas south from the cyclone to the New South Wales border.

A Queensland Fire and Emergency Service spokesman said there were more than 740 fire and rescue personnel, 11,500 RFSQ volunteers, 380 auxiliary firefighters and 1,300 SES volunteers ready to respond to the cyclone.

State Emergency Service volunteers had received more than 2000 requests for assistance in the past 24 hours, mostly in Brisbane and the north coast areas.

WHAT WE KNOW ABOUT CYCLONE MARCIA:

* Marcia was a category five cyclone when she made landfall, on the Capricorn Coast near Shoalwater Bay, at 8am (AEST) on Friday

* Australia has only seen five previous recorded category five storms hit its coastline, with the last being Cyclone Yasi, which hit north Queensland in 2011

* There were sustained winds near the centre of 205km/h, with wind gusts up to 285km/h

* It was moving south towards Yeppoon and Rockhampton at 20km/h

* Heavy rain has caused the Bruce Highway to be closed north of Rockhampton

* More than 600 people left their Yeppoon homes to bunker down at the town's evacuation centre

* Storm surges of up to 3m are expected along some parts of the Queensland coastline

* Across Queensland, 134 schools have been closed, along with 43 childcare centres and several TAFEs

* Marcia has forced Friday night's A-League soccer match between Brisbane Roar and Melbourne Victory at Suncorp Stadium to be called off

* Nine southeast Queensland dams are at full capacity and further heavy rain will ensure localised flooding, but the largest, the Wivenhoe Dam, is at 77 per cent of capacity and isn't expected to spill over

* 100,000 sandbags were collected from the Brisbane City Council's five depots by late Friday morning

- With Tony Moore, staff writers